[tip: core/stacktrace] stacktrace: Get rid of unneeded '!!' pattern

From: tip-bot2 for Jiri Slaby
Date: Mon Nov 11 2019 - 05:11:51 EST


The following commit has been merged into the core/stacktrace branch of tip:

Commit-ID: 4b48512c2e9c63b62d7da23563cdb224b4d61d72
Gitweb: https://git.kernel.org/tip/4b48512c2e9c63b62d7da23563cdb224b4d61d72
Author: Jiri Slaby <jslaby@xxxxxxx>
AuthorDate: Mon, 11 Nov 2019 10:26:47 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 11 Nov 2019 10:30:59 +01:00

stacktrace: Get rid of unneeded '!!' pattern

My commit b0c51f158455 ("stacktrace: Don't skip first entry on
noncurrent tasks") adds one or zero to skipnr by "!!(current == tsk)".

But the C99 standard says:

The == (equal to) and != (not equal to) operators are
...
Each of the operators yields 1 if the specified relation is true and 0
if it is false.

So there is no need to prepend the above expression by "!!" -- remove it.

Reported-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20191111092647.27419-1-jslaby@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/stacktrace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index c9ea7eb..2af66e4 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -142,7 +142,7 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store,
.store = store,
.size = size,
/* skip this function if they are tracing us */
- .skip = skipnr + !!(current == tsk),
+ .skip = skipnr + (current == tsk),
};

if (!try_get_task_stack(tsk))
@@ -300,7 +300,7 @@ unsigned int stack_trace_save_tsk(struct task_struct *task,
.entries = store,
.max_entries = size,
/* skip this function if they are tracing us */
- .skip = skipnr + !!(current == task),
+ .skip = skipnr + (current == task),
};

save_stack_trace_tsk(task, &trace);